a quadratic Bezier segment.

    Args:
        pt1: Start point of the Bezier as 2D tuple.
        pt2: Handle point of the Bezier as 2D tuple.
        pt3: End point of the Bezier as 2D tuple.

    Returns:
        Arc length value.

    Example::

        >>> calcQuadraticArcLength((0, 0), (0, 0), (0, 0)) # empty segment
        0.0
        >>> calcQuadraticArcLength((0, 0), (50, 0), (80, 0)) # collinear points
        80.0
        >>> calcQuadraticArcLength((0, 0), (0, 50), (0, 80)) # collinear points vertical
        80.0
        >>> calcQuadraticArcLength((0, 0), (50, 20), (100, 40)) # collinear points
        107.70329614269008
        >>> calcQuadraticArcLength((0, 0), (0, 100), (100, 0))
        154.02976155645263
        >>> calcQuadraticArcLength((0, 0), (0, 50), (100, 0))
        120.21581243984076
        >>> calcQuadraticArcLength((0, 0), (50, -10), (80, 50))
        102.53273816445825
        >>> calcQuadraticArcLength((0, 0), (40, 0), (-40, 0)) # collinear points, control point outside
        66.66666666666667
        >>> calcQuadraticArcLength((0, 0), (40, 0), (0, 0)) # collinear points, looping back
        40.0
    )